Homeostasis

• Homeostasis is essential for health and survival
• The body can maintain a relatively stable internal environment despite continuous changes in the external environment
• Homeostasis is the basis of most human functions
• Homeostasis is the process by which the body maintains a stable internal environment despite external changes
• Variables in the internal environment of the body fluctuate moment to moment throughout the day due to activities like eating, studying, physical activity, and even sleeping
• These fluctuations are normal as long as they do not become too extreme
• The body works to maintain homeostasis by keeping regulated variables within a normal range of values for optimal health
• Regulated variables are kept within a normal range of values for optimal health
• Feedback mechanisms (or loops) maintain homeostasis by constantly monitoring the internal environment for disturbances and making adjustments to maintain balance
• Disruption of homeostasis can lead to disease, illness, or death if the imbalance is not corrected
• Three essential components in negative feedback mechanisms that maintain homeostasis:

  1. Receptor (or sensor): detects a change in the regulated variable and sends information to the control center

  2. Control center: determines if adjustments are needed based on the 'normal' or 'desirable' set point

  3. Effectors: target cells, tissues, or organs that carry out actions to respond to the initial change
• Control centers are often located in the brain or an endocrine organ
• Effectors increase or decrease their activity to oppose the initial change and bring the variable back to the normal range
• As the variable returns to the normal range, the activity of the effectors returns to their normal resting levels until another change is detected